<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
    <title></title>
    <script src="js/jquery-3.2.0.js" type="text/javascript"></script>
</head>

<body>
<div>元素一</div>
<div>元素二</div>
<div>元素三</div>

    <script type="text/javascript">

    		var div = document.getElementsByTagName('div'); //dom对象
            var $div = $(div);
		    //将dom节点div转化为$div的jquery对象
            // $div =  ?
             
			$('div:eq(0)').css('color', 'red'); //给第一个元素设置颜色
            $('div:eq(1)').css('color','yellow');//给第二个元素设置颜色
            $('div:eq(2)').css('color','blue');//给第三个元素设置颜色
            
    </script>







</body>

</html>